Edge illuminated instrument panel



Patented Apr. 27, 1954 UNITED f? ATENT OFFICE EDGE ILLUMINATED INSTRUMENT PANEL Application October 13, 1950, Serial No. 189,963

2 Claims.

This invention relates to electric lighting devices and more particularly to illumination of panels by edge lighting thereof.

An object of the present invention is to provide an electric light assembly ioredge lighting a panel having'an improved construction'aiiording a compact arrangement of parts which presents a minimum of structure protruding from the exterior and visible face of the panel.

Another object of the invention is the. provision in a lighting device of the character indicated of a construction whereby it may be readily and easily mountedon a panel and once mounted is securely maintained.

Another object of the invention is to provide an improved construction for a panel illuminat ing electric lighting device having its component parts particularly :formedran-d organized to facilitate rapid assembly and disassembly thereof whereby the device may be readily removed for replacement or repair.

A further object islto provide a novelvform of lighting device having-an improved construction which lends itself economy of manufacture invention. I Figure '2, is a ,perspective view .oi the retaining element.

Figure 3 is a fragmentary ,perspective'view of a. modified form of .ret'ainin-gi'element.

Figure 4 is a longitudinal sectional view of a modification of the electric light assembly; and

Figure-5 is a perspective view of the retaining elementof the light assembly of Figure 4;

In the drawing the numeral 10 indicates a panel and the numeral l I generally inclicates'theelectric light assembly of. the present invention. The panel I!) may constitute an instrument panel, switch panel, circuit breaker panel, radio panel, instruction panel or like member, and may have lettering, indicia, or any variety or form of markings applied thereon which will beilluminatcd by the rays of light provided in the panelby the electric light assembly H. The panel is formed of a suitable translucent organo-plastic material which readily conducts light wit-ha minimum loss of light. The material use d 'maybevinyl resin,

cellulose acetate or methyl methacrylate which is sold commercially under the trade-mark Lucite. The rear surface of the panel is preferably smooth and glass-like and will reflect the light inwardly to increase the illumination available at the face of the panel. The-desired smoothness of surface is readily attained in the molding operation.

A metallic mounting plate i2 is provided at the rear face of the panel ID to which the panel is is secured in anysuitable manner. Suitable means retain the mounting plate I 2 in place. It is understood that the precise manner of holding the panel it on plate 12 and of securing plate I2 at a desired position forms no part of this invention. An aperture I3 is provided in panel In in alignment with an aperture l4 afforded in mounting plate i2, through which apertures the electric light assembly H extends for mounting thereof upon panel 10. Surrounding aperture It the mounting plate [2 is grooved or recessed at is to effect aninwardly directed flange or ledge It which assists in-the-support of the light'assembly i l, as will'bellater'described.

Electric light assembly ll includes *a hot ising ll, a terminal assembly lBsupported at one end of the housing ll, an incandescent'lamp Henclosed by housing i7 and a metallic retaining member or cap 25. The housing f1 comprises a v"generally cylindricalshell 21 having an outwardly projecting flange'ZZ at one end, an internally threaded portion 23 adjacent this one end, and at-its other end having its interior surface cut away as at 24 to-fo'rm-an internal shoulder'or seat against which a contact carrier ring,

orbase, 25 made of a suitable insulatingimaterial, abutstoclose this end of theshellzl. Contact carrier ring 25.forms apart of'the'terminal assembly l8 andis secured to the end of shell 2! by spinning or staking the end of'she'll 2!, as shown at 25, to project a portion of the shell into anannular peripheral groove 2'! centrally provided in the vexterior surface of thering 25. Contact carrier ringtt .is provided with acentral aperture 28 in whichis'mounted a metallic'guide bushing or eyelet 29, the interior "end 'of which is outwardly turned as at 3| andgpressed into engagement with the interior face- 0f ring 25. Terminal assembly [8 also includes a terminal lug 32, which "maybe connected in "any'su'itable manner to a source of electrical energy, not shown, and which is supported at the exterior face 33 of ring 25, with a'washer -34 interposed between a leg of lug 32 and the face 33 of ring 25. The exterior and of eyelet 29 is turned 3 to form a flange 36 which clamps the lug 32 and the Washer 34 to the ring 25.

A metallic sleeve or conductor element 3'! is slidably fitted in the bore of eyelet 29 and extends from within the housing l'l' through the eyelet 29, and aligned openings provided in washer 34 and leg 35 of lug 32 to project to the exterior of the housing [1. A contact 38 is carried at the interior end of metallic sleeve 37 for movement therewith. Completing the terminal assembly i8 is a spiral spring 4! which is fitted about and surrounds the interiorly disposed portion of me tallic sleeve 37. One end of spring 4| seats upon the turned end 3| of eyelet 29 and the opposite end abuts the rear face of contact 38. Spiral spring ii exerts its bias to force metallic sleeve 31 forwardly into housing Il The outer end of metallic sleeve 37 is flared as at 42 for abutting engagement with the eyelet flange 36 to limit the extent of inward movement of sleeve 31 into housing [1.

Movable contact 38 is adapted to be engaged by base contact 43 of incandescent lamp I9 when the latter is inserted into elongated shell 2! through the opening thereof. Lamp I9 is of conventional construction and comprises a glass bulb 44 within which is located a usual filament 45 having one-terminal, not shown, connected to base contact 43 and its other terminal, not shown, connected to a metallic sheath 46. To maintain the lamp IS in operative position within housing i! there is provided the metallic retaining member or cap 23. Cap 20 may be formed of aluminum or any other suitable-conducting metal and as best shown in Figure 2 comprises an annular head portion 47 of greater diameter than aper- .ture l3, and a generally cylindrical body portion shell 2!.

Encircling the section of body portion ta-having the openings 5| and 52 is an annular transjlucent filter member 54 of any desired color which is adapted to lie in aperture l3 of panel [0 with .its base resting on flange 22 of housing IT, and being retained in aperture l3 by a rubber washer or cushioned member '55. Washer 55 is of greater diameter than. aperture I3 and is disposed on body portion 43 .of cap 20 between the filter 54 i and the rear surface of the, caps head portion 4'! and will be forced against filter 54 and the face of panel ii! when cap 26 is threaded into housing i1. Filter 54 is made of suitable translucent plastic material such as that employed in the manufacture of panel It and may be of any desired color to provide colored light within the panel it when lamp l9 is on. It has been found advantageous in aircraft usage to light various instruments on the instrument panel with a soft light to lessen the chance of confusion when the viewer transfers his gaze from outside the airplane to the instrument panel. The color red is particularly preferred for an aircraft panel for it provides non-glaring illumination of the instrudition.

The lower end 56 of body portion 48 is adapted to engage a flange 51 on sheath 4-6 of lamp It to thereby move the lamp i9 rearwardly into housing I! against the bias of spring 4| as cap 20 is threaded into housing IT. In this movement lamp contact 43 engages movable contact 38 to complete the lamp circuit. To facilitate the movement of cap 23 into housing ll the head portion 4? is slotted to receive the end of a screwdriver.

To secure housing H to mounting plate I2 the housing I! is externally threaded as at 58 and carries a nut 34, a lock washer 32 and a washer 63.

Figure 1 illustrates the electric light assembly H in mounted position on panel 13. Assembly Il may be attached to panel I!) while in fully assembled position, with lamp I?! in contacts engaged position, the filter 54 disposed adjacent the openings 5! and 52 and cap 2c threaded into shell 2|. To mount assembly H it is necessary only to insert the housing I! into the aligned apertures l3 and I4, provided in panel I0 and mounting plate I 2 respectively, and move the assembly ll inwardly until flange 22 on shell 2| abuts ledge 15 on mounting plate l2. Washer 33,

lock washer 62 and nut 6! are then fitted on the exterior of shell 2i"and nut 6| rotated until washer G3 is tightly pressed against the rear face of mounting plate I2 to clamp ledge l3 between the washer 63 and flange 22 of shell 2|. With this construction it is apparent that the light assembly Il may be easily and readily removed from the panel for inspection, repairs or replacement.

It is to be noted that head portion 41 of cap 23 protrudes only a slight amount beyond the front face of panel Ill. The height of head portion A! is only as great as is necessary to conveniently permit the use of a tool to manipulate cap 28. Holding the height of head portion 41 to a minimum height is of advantage in that it permits easier scanning of the panel lettering and objects, it is much less likely to cause confusion between it and knobs of circuit breakers having deceptively similar appearance, and further it others less of a hazard'to aircraft crew members who work in a small enclosure and who would be much less likely to inadvertently strike against it.

Figure 3 illustrates a modification of a retaining cap member for the electric light assembly.

As shown the modified cap member, which is here indicated generally by the numeral 65, comprises an externally threaded body portion 6'6 having opposed openings 61 and 68, and a head portion 697 Head portion 69 difiers from head portion 41 of cap 20 in that instead of employing a slot there is formed a central projection H on the front face of the head portion '59, which projection H may be grasped by pliers for ready manipulation of the cap member 65. Again the height of head portion 69 is held to a minimum. Head portion 69 with its projection H is of not much greater height than head'portion 41 with its slot for receiving the end of 'a screw driver. Only a sufiicient height is provided the projection H to enable it to be readily grasped by pliers.

The modification illustrated in Figures 4 and 5 differs from the structure hereinbefore described essentially in the form of the retaining cap member and the manner of providing colored light into a panel.

The modification of Figure 4, similarly to the modification of Figure 1, embodies a generally 4| projects the sleeve 31 into shelhiil cylindrical :shell12 |v :having a projecting flange 22 at one 'end, an internallythreaded section 23 adjacent this end; and an internal shoulder 24" at the; opposite end. A terminal: assembly iilis supported at this: opposite end; This terminal assembly it, as: in the :first embodiment, includes an insulating contact carrier'ring which is secured. to shell 2| by spinning the end of shell 2|, an eyelet 19' toxwhich is secured a ter- .65 .hereinbefore .described.

Cap member 13 .embodiesa. metallic generally cylindrical element It having an externally threaded portion 15..and:a-.portion it of reduced diameter having ..its exterior surface knurled. An internal groove 13: is :provided in portion 75 adjacent the outer end thereof and receives a ring-type spring [8 which exerts its force to support the lampv lawithinhcap 1'3. Secured to the portion 16 of metallic element M is a trans lucent cylindrical element 8| formed of a suitable translucent plastic material which material may be the same as the material used in making panel H) and filter 54. By employing a translucent element 8| in the construction of the cap member 13 it is obvious that a filter 54 need not be used. The material of the plastic element 8| may be colored, and be of any desired color, for the same purpose as filter 5% is colored.

Translucent cylindrical element BI is rabbeted at one end and internally as shown at 82 to accommodate the reduced diameter portion E6 of metallic element I4. Plastic element Si is secured to metallic element 14 by hot-forming the rabbeted portion 82 of element 8| aboutthe knurled exterior surface of portion 16, or may be secured by the use of a suitable commercial nection between elements M and 8| forms no cement. The exact method of effecting the connection between elements it and 8| forms no part of the present invention and therefore any well known expedient may be employed. Thus the metallic cylindrical element M and the translucent element 8| cooperate to form the body portion of cap member 13 which envelops the lamp l9, and to which the lamp I9 is releasably secured by spring 18.

A rabbet 83 is provided at the opposite end of the translucent element 81 and receives a rubber washer or cushion 84. Fitted to this same end of element 8| is a head element 85 formed of hard rubber and comprising a disk portion 86 and a shank portion 81 which projects into the end of element 8|. The head element 85 is secured to element 8| either by molding or by the use of a suitable cement. Again the method of connecting one element to the other is not a part of the invention and any conventional method may be utilized. The exterior face of head element 85 is slotted to enable manipulation of the cap member 13 by means of a screw driver. Rather than a slot the face of head element 85 could be formed similarly to head portion 69 of the modified cap member 65 illustrated in Figure 3.

In mounting the modified electric light assembly of Figure 4 the shell 2| carrying the terminal assembly I8 is inserted through aper- 6 ture M of mountingrtplate 1-2. to .rest flange 22 upon ledge It. To clamp shell 2|: to mounting plate l2 shell 2| carries thev nut 6| with interposed washer 63 andlock washer 6'2. Tightening of nut 6| will efie'ctively secure the shell 2| to mounting plate l2. After the shell 2| has been mounted the panel I0 is placed uponmounting plate l2 and the cap member 13 carrying lamp I9 is inserted. through an aperture 88 and rotated to effect a threaded engagement between internally threaded section 23 of shell 2| and externally threaded portion 1.5 of element 14. It is noted that aperture 88in panel ID- in the present modification is. of smaller diameter than aperture I3 in panel H! of the first described modification.

Aperture 88 does not. permit the passage of shell 2| therethrough and is of sufficient size only to accommodate capv member 13. Head element is of greater diameter than aperture 58 and thus when cap member i3 is moved into threaded engagement with shell 2| the cap member 13 'exerts'a clamping force upon panel I0 and serves to support panel lii on' mounting plate l2. If desired other suitable mounting means, not shown, may be employed to assist in securing the panel Hi to mounting plate l2". In the mounted position of cap member 13 the lamp I9 is positioned adjacent the edges of panel l0 and the light therefrom passes freely through translucent element 8| and into the panel ID for illumination thereof.

Cap member 13 can be readily withdrawn and will carry lamp H! with it to permit inspection or replacement thereof.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What I claim is:

1. The combination with a translucent panel of a device for illuminating the panel, said panel having an aperture therein, a mounting plate contiguous the rear face of said panel, a substantially cylindrical elongated shell having an opening aligned with said aperture, threads provided on the interior wall of said shell, means for removably securing said shell to the mounting plate, a contact movably mounted within said shell, a lamp disposed'within said shell for projecting light into the edges of the aperture in the panel, a contact on said lamp engaging said movable contact, a retaining means for holding said lamp within said shell with the contacts in engaged position, said retaining means comprising a head portion positioned at the front face of the panel which overlies and closes the aperture in the panel for sealing on said lamp and clamping the panel to the mounting plate and a generally cylindrical body portion having an axial bore therein into which said lamp extends, which body portion projects through the aperture and into the shell, said body portion comprising an externally threaded metallic portion engaging the interior threads of the shell to secure the retaining means to the shell and a translucent portion connecting said metallic portion and said head portion and which lies adjacent the edges of the aperture in the panel to permit the light from the lamp to pass thereinto, and spring means carried by the metallic portion for mounting said lamp to said body portion.

2. The combination with a translucent panel of a device for illuminating the panel, said panel having an aperture therein, a mounting plate contiguous the rear face of said panel, a substantially cylindrical shell opening at one end onto said aperture, threads provided on the interior wall of said shell, means for removably securing said shell to the mounting plate, a terminal assembly carried at the opposite end of the shell comprising an insulating base which closes said end of the shell, a contact, and springbiased means movably mounting said contact, a lamp disposed within said shell for projecting light onto the edges of the aperture in the panel, a contact on said lamp engaging said movable contact, and retaining means for holding said lamp within said shell with the contacts in engaged position, said retaining means comprising a head portion positioned at the front face of the panel which overlies and closes the aperture in the panel for sealing off said lamp and clamping the panel to the mounting plate and a generally cylindrical body portion having an axial bore therein into which said lamp extends,

which body portion projects through the aperture and into the shell, said body portion comprising an externally threaded metallic portion engaging the interior threads of the shell to secure the retaining means to the shell and a translucent portion connecting said metallic portion and said head portion and which lies adjacent the edges of the aperture in the panel to permit the light from the lamp to pass into said edges, and spring means carried by the metallic portion for mounting said lamp to said body portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,739,954 DuPont Dec. 17, 1929 1,973,908 McIlwee Sept. 18, 1934 2,199,790 Batcheller 1 Mar. 1, 1938 2,144,138 Batcheller Jan. 17, 1939 2,220,515 Foute Nov. 5, 1 40 2,242,165 Batcheller May 13, 1941 2,278,840 Douglas Apr. 7, 1942 2,413,381 Rylsky Dec. 31, 1946 0,2 Paulus Apr. 2'7, 1948 

